An apparatus and method of integrated billing management by real-time session management, and a computer readable medium thereof are provided. The integrated billing management apparatus performs billing management functions, that is, analyzes various messages related to the billing service request, manages sessions in real time, processes reliable billing information data and generates formulaic billing information. Then, the integrated billing management apparatus transmits the result of processing the billing service to the user terminal through the network access device. Therefore, the customer discontents can be responded in real time and customized billing management service based on the amount of service used can be provided form all wired and wireless network services.